Abstract
This paper investigates the energy characteristics of the concentric heat pump. The heat exchanger of the evaporator of the "pipe in pipe" type, through the inner copper tube of which the refrigerant circulates, and inside the outer pipe - the coolant, is placed in a spiral around the compressor, cooling it and at the same time absorbing the heat released by it. The new design improves technical and economic performance. Experimental results were carried out, which confirm the possibility of maintaining the compressor temperature (80-90°C), increasing the heat output and conversion coefficient (COP) by an average of 10-15%. The proposed technical solution makes it possible to improve the energy efficiency of the concentric heat pump due to the absorption of the excess heat from the evaporator in the general heat flow and to reduce the emissions of CO2.